Mammillaria (Bartshella) insularis
The flowers are very showy and
nearly as large as the plant bodies.
Description: Sometimes solitary this species
may forms groups, but it grows very slowly and it can take much time
until a stem branches for the first time.
globose to depressed
conical when growing in
habitat. While cultivated plant have (frequently)
offsetting , green or grey-green
epidermis that tinge, Up to 6(-9) cm tall, 5(-9) in diameter
Flowers: Showy, nearly as large as the plant
bodies up to 3 cm long (or more), from
almost full white to pink with white edges to completely pink, .
Blooming season: Midsummer
insularis H.E.Gates ex Shurly
Cact. Succ. J. Amer. 10: 25, 1938
Origin: Mexico, Baja California peninsula, endemic of
islands (Isla Angel de la Guarda, Isla de San Marcos, Isla Piojo, Isla
Smith, Isla Ventana) and area around Bahia de Los Angeles
Conservation status: Listed in
CITES appendix 2.
M. insularis was
once placed in the
genus Bartschella because of its fruit
anatomy and large pink flowers located at the top of the plant. The
fruit are red, thin-skinned and often break off from a basal
pore rather than falling whole (like in most Mammillaria).
- Ebnerella insularis(H.E. Gates) Buxbaum 1951
- Chilita insularis (H.E. Gates) Buxbaum 1954
- Bartschella insularis
- Neomammillaria insularis (H.E.Gates) Y.Itô
This cactus with its wonderful large flowers make
an interesting addition to any collection.
Cultivation: This plant is
somewhat difficult to cultivate. During the summer it is best to
keep the plants outside where the temperature can rise to over 30 C with
no harm to the plant. Furnish good drainage and use a an open and free
draining mineral compost that allows therefore roots to breath
(as it is
rot prone) It likes a winter's rest and should be kept
almost completely dry during the winter months, If the soil is allowed
to be dry for too long root loss could follow but equally the same
result would occur if the plants are both wet and cold. From March
onwards the plant will begin to grow and watering should be increased
gradually until late May when the plant should be in full growth. Water
regularly during the summer so long as the plant pot is allowed to drain
and not sit in a tray of water. During hot weather you may need to water
the plants more frequently so long as the plant is actively growing.
From late September watering should be reduced to force the plant to go
in to a state of semi dormancy, by October you should be back in to the
winter watering regime.
Need full sun avoiding only the harshest summer sun, if kept too dark
they may become overly lush and greener and could be prone to rotting
due to over watering.
Feeding may not be necessary at all if the compost is fresh then, feed
in summer only if the plant hasn't been repotted recently. Do not feed
the plants from September onwards as this can cause lush growth which
can be fatal during the darker cold months. Grown
specimens resist to -4°C for a short time, but it is best to keep above
5° C to avoid ugly spots on the plant epidermis.
Propagation: Direct sow after last frost.
(seldom produces offsets)